Back-gearing mechanism



(No Model.) 3 Sheets-Sheet 1.

' B. G. LUTHER.

BAGK GEARING MECHANISM. No. 446,233. Patented Feb. 10, 1891.

' MAM wo d melx, W, Y

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(No Model.) 3 snee ts-sheet 2.

B. G. LUTHER, BACK GEABING MECHANISM.

No 446,233. Patented Feb; '10, 1891..v

(No Model.) 3 Sheets-Sheet 3.

r B. G'. LUTHER. BACK GBARING MECHANISM. v No. 446,233. Patented Feb. 10, 1891.

ml: mama PETERS cm, PumMrmm, msumufuu, n. c.

' UNITED STATES PATENT Enron.

BENJAMIN G. LUTHER, OF \VOROESTER, MASSACHUSETTS.

BACK-G'EASRING MECHANISM.

SPECIFICATION forming part of Letters Patent No. 446,233, dated February 10, 1891.

Application filed October 17, 1890. Serial No. 368,484. (No model.)

T at whom it may concern:

Be it known that I, BENJAMIN G. LUTHER, a citizen of the United States, and a resident of Vorcester, in the county of Vorcester and State of Massachusetts, have invented certain new and useful Improvements in Back-Gearing Mechanism for Machines, of which the following, in connection with the accompanying drawings, is a specification.

My invention relates to machines in which the working efiect may be increased at will by the use of back-gearsas, for instance, in engine-lathes, drills, &c.and has for its object to provide simple and eitective means whereby such back-gears may be connected with or separated from the driving-pulley by a movement of a hand-lever whether the machine is running or standing still.

In machines of the kind above mentioned considerable delay has always been caused when throwing the back-gears in or out of engagement with the spindle, inasmuch as the facegear must be disconnected from the cone by loosening the cone-stud and slipping the same out of the cone and clamping it. again on the face-gear, all of which could be done only when the machine was at a standstill. After this the quill of the back-gears must be moved so as to bring the back-gears in engagement with the gears on the spindle. Sometimes when cuttinga screw in the lathe the spindle must rotate very slowly; but it is desirable to return the cutting-tool to its starting-point at a considerably accelerated speed in order to gain time.

In the lathes as built heretofore too much labor is involved in throwing the back-gears out of action, in order to allow a quick return of the cutting-tool, and the former would have to be thrown into action again before the tool commences to take the succeeding out.

In my present invention all this delay and labor is avoided, since by a slight movement of a hand-lever the back-gears may be brought into or out of engagement at will, as will be readily understood by referring to the accompanying drawings, in which- Figure 1 is a side view of the head of an engine-lathe embodying my invention. Fig. 2 represents a horizontal section through the spindle, the back-gears being shown in action. Fig. 2 is a detail view showing a modification. Fig. 3 represents a similar view showing the back-gears disconnected. Figs. 4 to 8, inclusive, are perspective views of some of the details. Fig. 9 is a cross-section on line w w of Fig. 1. Fig. 10 isa cross-section on line y y of Fig. 1. Fig. 11 is a section similar to that shown in Fig. 10, representing the same parts in a different position. Fig. 12 is a side View of the pinion on the spindle. Fig. 13

represents'a modification showing a supporting-shell surrounding the shaft, such construction being desirable in the larger machines.

In the drawings, A represents the headcasting of an engine-lathe, supporting in the bearings C6 the spindle B, upon which the cone-pulley O is mounted.

D represents the pinion, having a hub 12 and loosely supported on the spindle B.

E is the back-gear, mounted upon the quill F, the other end of which is formed into the back pinion F, which meshes into the facegear G, loose upon the spindle. The quill F is supported on a stud a, firmly held in the ear a of the head-casting, and is prevented from side movement by the nut 0. at the end of the stud a The face-gear G carries one or more dogs 0, (see Fig. 9,) which are pivoted at c, and the loose ends of which are thrown toward the spindle by means of springs 0 resting with one end against the back of the dog and with the other against the pin 0 The dog 0 is provided with a tooth 0 which is adapted to enter the notches d in the collar cl, and thus form a connection between the face-gear G and spindle B, so that any rotation of the gear will cause a like rotation of the spindle.

The face-gear G has openings 0 (see Figs.

2, 3, and 9) to loosely receive projections c,

case the gear G would be entirely loose upon the spindle B.

The slide II consists, essentially, of a flanged ring (see Fig. 6) having two spurs e diametrically opposite each other and of a width equal to that of the openings 0 in the facegear G, the whole being supported on the outside of the hub of said facegear, where it can move back and forth lengthwise, but must rotate with the gear.

Referring to Figs. 1.0 and 11 of the drawings, it will be seen that the cone-pulley C carries two dogs J, which are pivoted at f and have a tooth f while the springs f serve to swing their free ends toward the spindle, which is provided with the collar g, firmly secured thereto by the key g. The collar g is provided with notches 9 with which the said tooth f of the dog may engage, whereby the cone-pulley C will be connected with the collar g, and thereby with the spindle l3, such condition being represented in Fig. 11.

The cone-pulley is disconnected from the spindleinthe following manner: Supportedon the outside of the hub of the pinion D, which is loose on the spindle 13, is the slide I, consisting of a flanged ring provided with the spurs 2', which pass through and are of a width equal to that of the openings h in said pinion D. It will therefore be understood that although the slide I may move lengthwise on the hub of the pinion the rotary movements of both are simultaneous. IVhen now the slide I is moved toward the cone-pulley (J, the spurs i will be carried into the path of the ends of the dogs,which will then ride upon the said spurs, and thus draw the teeth f out of the notches 9 thus liberating the conepulley from the collar, and consequently from the spindle. If the rotary movement of the cone is still continued, the teeth f will encounter the spurs z and carry them along, whereby a rotary movement will be imparted to the pinion D, and thus to ,the gears E, F, and G.

The slides 11 and I are provided with flanges, so thatI am enabled to employ the shell J for operating both slides in unison, said shell .I being made in halves, which are fastened together by the sorewj, and each of which is provided on its side with a pin j to fit the bifurcated ends of a fork K, which latter is secured upon a spindle k, to which a rocking motion may be given by the hand-lever L on the outside of the head-casting, or by lever M and a rod M, which runs inside the lathebed and above its ties, so that the back-gears can be thrown in or out of engagement from any point lengthwise of the machine.

If the back-gears are running, such condition. being illustrated in the drawings, and it is desired to change into the more rapid cone speed, the operation is as follows: The handle L is to be raised, by which action the shaft will be rocked and a similar movement will be imparted to the fork K, which operates upon the slides II and I, moving the same'from left to right. The slide II in its movement toward the face-gear swings the dogs 0 around their pivot, by which movement their teeth 0 are drawn out of the notches d in the collar cl, so that all connection between face-gears G and collard or the spindle is completely severed, leaving the .come to a place over the notches 9 into which the spring f will drive the same, so that a' driving connection will thus be made between the cone-pulley and collar, and consequently with the spindle. The pinionD will now be perfectly loose upon the spindle, because the only means for connecting the same with the dogs of the cone-pulley have been withdrawn by the movement of the spurs 2'. (See Fig.3, which repres'entsthe backgears out of engagement.)

By referring to Figs. 9, 10, and 1] itwillbe seen that the sides of the notches (Z' and 'g in the collars and the teeth 0 and f of the dogs are slightly beveled and the pivot-pins c and f are surrounded by rings 0 and f, which are made of leather or some other yielding substance. By this construction the beveled sides of both teeth will be allowed to come/to a full bearing in their respective notches in the collars, so that any slight variation in placing the dogs or forming the notches will be remedied, inasmuch as the dogs will adjust themselves on account of the yielding rings 0 and f I11 Fig. 13 is represented a modification of the above-described construction to be employed in lat-hes of large sizes mainly, as it is desirable to relieve the spindle of the weight of the gears and the operating -slide,'as follows: Instead of placing the gear directly on the spindle, I provide a sleeve N, having a flange 77, on the outside of which the gears D and G are supported in running fit, while its inside diameter is large enough to allow the spindle B to loosely pass through the same. The sleeve N forms part of a casting, which may be secured by its foot N to the head-casting, so that the weight of the parts which are supported on said sleeve will be taken off the spindle, thus saving the wear of the latter. In this construction it is necessary to leave a space between the flanges of the slides II and I, and the flange n of the supportingsleeve serves as a stop for the said slides in both directions, the slides being connected to move together by the shippers O, which are operated by the ends of a fork similar to the one above mentioned engaging the pins 0.

In Fig. 2 is illustrated a modification which is especially adapted for use in lathes of smaller sizes. In this instance the pinion D and the spurs i are cast in one piece, and the IIO huh I) is beveled at its end to operate the dogs c in the same manner as the slide II and its prongs 6, previously described. The hub 19 of the pinion is provided with an annular groove Z, which receives the pins Z of the fork K, so that the pinion D is moved by said fork K, producing the desired results by operating the dogs f and c, the latter of which are placed on that side of the gear G which faces the cone,

so that the above-mentioned holes or openings 0 are unnecessary.

I claim as my invention 1. The combination, with the spindle provided with a notch adapted to be engaged by a driving-dog, of the cone-pulley provided with a spring-actuated driving-dog having an engaging tooth which is adapted to enter the notch of the spindle, and the movable spur which is adapted to engage with the dog to cause the withdrawal of its tooth from driving engagement with the notch to driving engagement with the spur, substantially as described;

2. The combination, with the spindle provided with a notch adapted to be engaged in both directions by a driving-dog,of the conepulley provided with a spring-actuated driving-dog having an engaging tooth which is adapted to enter the notch of the spindle and cause the movement of the same in either direction, and a movable spur which is adapted to engage with the dog from either direction to cause the withdrawal of its toot-h from driving engagement with the notch to driving engagement with the spur, substantially as described.

3. The combination, with the spindle provided with a notch adapted to be engaged by a driving-dog, of the cone-pulley provided with a spring-actuated driving-dog adapted for engagement with the notch to cause the rotation of the spindle and the loose pinion which holds a spur adapted for engagement with the dog to cause the withdrawal of its tooth from driving engagement with the notch of the spindle to driving engagement with the spur to cause the rotation of the pinion, substantially as described.

4:. The combination, with the cone-pulley and the gear, which are arranged loosely upon the spindle and each provided with a springactuated driving-dog, and the spindle provided with notches adapted to be engaged by the driving-d ogs of the cone-pulley and gear, of the loose pinion which holds a spur adapted for engagement with the dog of the conepulley to cause the withdrawal of its tooth from driving engagement with its notch to driving engagement with the spur of the pinion, the intermediate gears which connect the pinion and the loose gear, and meansfor effecting the engagement and disengagement of the driving-dog of the gear in timely relation to the disengagement and engagement of the driving dog of the cone-pulley, substan tially as described.

5. The combination, with the gear carrying a spring-actuated driving-dog, of the spindle provided with a notch which is adapted to be engaged by the tooth of the dog, so as to be capable of rotation in either direction by the said dog, substantially as described.

6. The combination, with the loose gear carrying a spring-actuated driving-dog, and the spindle provided with a notch which is adapted to be engaged by the tooth of the dog, of means, substantially as described, whereby the dog can be raised out of the notch of the spindle, as set forth.

7. The combination, with the spindle, of the pinion, the loose gear, the intermediate gears, and the fixed standard adapted to support the pinion and gear from hearing directly upon the spindle, substantially as described.

8. The combination, with the spindle, of the cone-pulley having a spring-actuated dog, a notched collar on the spindle, adapted to be engaged by the tooth of said dog, a sliding spur for raising said dog out of engagement with the notches of the collar into engagement with the spur, the pinion, the intermediate gears, the loose gear upon the spindle, its spring-actuated driving-dog having a tooth adapted to engage with a notch in the spindle, a slide whereby said dog is disengaged from its notch, and means, substantially as described, whereby the said slide and the sliding spur are moved simultaneously, for the purpose set forth.

9. The combination, with the spindle provided with engaging notches and the conepu-lley, of the spring-actuated driving-dogs having yielding rings upon their pivots, which will allow both of said dogs to come firmly into engagement with the notches of the spindles, substantially as described.

BENJAMIN G. LUTHER.

lVitn esses:

JOHN S. LYNCH, SOCRATES SCHOLFIELD. 

